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Finding the Fourth Proportional to 63.18, 86.84 and 56.90

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Solution

The fourth proportional to 63.18, 86.84 and 56.90 is: 78.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.18 : 86.84 = 56.90 : x
  2. Step 2: Convert to fraction form
    63.18/86.84 = 56.90/x
  3. Step 3: Cross multiply
    63.18x = 86.84 × 56.90
  4. Step 4: Simplify right side
    63.18x = 4,940.48
  5. Step 5: Solve for x
    x = 4,940.48/63.18
  6. Step 6: Final answer
    x = 78.20

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.